The cancer-causing herbicides dubbed "Agent Orange" were sprayed by the B.C. government during the ‘60s and ‘70s, according to documents obtained by CTV News.

Records show tens of thousands of gallons of the toxic mixture were applied to clear brush near highways and along power lines in the late 1960s and early 1970s – and in some cases the substance was sprayed next to homes.

"It was a real strong smell. You couldn't get away from that smell. We smelt that for a year straight in our house, couldn't get rid of it," recalled former Cherryville resident Larry Heal, who remembers a BC Hydro crew spraying a pungent chemical along the high voltage power lines next to his family's home.

"All that stuff went into the creek, so we drank it. All that stuff got in the cow, and we drank the milk. Our clothes were washed in it, our dishes were washed in it," he recalled. "We didn't know what it was."

Heal says more than three decades later his sister has died of adrenal cancer, and he has contracted a yet-to-be explained problem with his nervous system.

"I feel disgusted. I fought pain all my life, and I never knew why," he said, adding he hopes the government will probe the use of the chemicals and compensate those affected.

A CTV News investigation uncovered several hundred pages of documents that show the routine process by which district engineers ordered the chemicals 2-4-D and 2-4-5-T in 45-gallon drums.

The combination of those two herbicides in equal parts comprised Agent Orange, which was used to strip jungle cover and expose North Vietnamese fighters during the Vietnam War. Some 12 million gallons were sprayed over the Vietnamese jungle and the chemical has become notorious for its connection to cancer and birth defects among Vietnamese children.

In 1970, a study showed that dioxin-tainted 2-4-5-T caused birth defects in laboratory animals. After that, the U.S. military stopped using Agent Orange in Vietnam. According to the U.S. Department of Veterans Affairs, some 50 diseases and medical conditions are associated with exposure to the chemical.

While 2-4-D is still used today, 2-4-5-T use is major health hazard because it was contaminated with dioxin, according to Agent Orange expert Wayne Dwenychuk.

Dioxin is a potent carcinogen that can lead to a number of health problems, including cancer and neurological diseases, and is banned in Canada today, Dwenychuk said.

"If they used 2-4-5-T through B.C., they were spreading dioxin; there's no doubt in my mind," he said, adding that the biggest concern is for those who were employed by the government to apply the herbicide.

In B.C., the mix of 2-4-D and 2-4-5-T was called "Type B Weed and Brush Killer" in government invoices. Sometimes, the engineers ordered 2-4-5-T by itself, and dubbed it "Type C Weed and Brush Killer."

In total, about 26,000 gallons of Type B Weed and Brush Killer were ordered between 1965 and 1972. About 10,000 gallons of Type C Weed and Brush Killer were ordered in the same time period. The barrels were shipped to all four of the regions of B.C. as designated by the Ministry of Highways: Kamloops, Nelson, Prince George and Vancouver.

Simon Fraser University epidemiologist Scott Venners told CTV News that dioxin latches onto fat cells and can stay in the body for a long time. He said it's possible even a single large exposure could cause lasting disease.

"If you had exposure to dioxin it's plausible you could have health effects, cancer, fertility and immune system problems," he said.

It's possible that some of the chemical remains in the sprayed areas today, he said.

In the early 1970s, several community groups wrote the Ministry of Highways to complain about the use of 2-4-5-T by the government, the documents show. The ministry responded by slapping a ban on herbicides on highway rights-of-way in 1973.

But that left about 6,000 gallons of toxic herbicides in stock, a letter from Michel Pope, Senior Landscape Supervisor, says on April 2, 1975.

"The department had a considerable amount of herbicides in stock and this has been retained in the event that the ban might be lifted," he writes. "However, the containers in which the material is stored are beginning to deteriorate to the point where certain environmental damage might occur."

The BC Hydro and Power Authority was willing to buy all of the chemicals at "half price," he wrote.

In 1976, documents from BC Hydro show 2-4-5-T and 2-4-D was sprayed along Hydro lines Vernon-Monashee and Nicola-Brenda circuits, including the area next to Larry Heal's house.

The documents also say "brushkiller" was sprayed in Pemberton and Daisy Lake.

When CTV News first contacted BC Hydro about spraying, a spokesperson denied ever using the chemicals, saying in an email "Historical Hydro data indicates that BC Hydro has never used Agent Orange."

Two months later, after CTV News obtained the documents under the Freedom of Information Act, the utility admitted using 2-4-D and 2-4-5-T until September 1976. It said "brushkiller" was 2-4-D but may have contained 2-4-5-T. "There are no more details available about this," a Hydro spokesperson said.

But executive vice-president Greg Reimer said that doesn't mean the agency used "Agent Orange."

"BC Hydro never used Agent Orange…in performing vegetation management on the provincial electricity system," Reimer said in a written statement.

Dwernychuk said Hydro is splitting hairs.

"If Hydro used a mixture of 2-4-D and 2-4-5-T in a one-to-one proportion, it was, for all intents and purposes, Agent Orange," he said.

B.C.'s Ministry of Transportation also denied that Agent Orange was ever used in the province., but admitted using 2-4-5-T and 2-4-D. In 1978, 2-4-5-T was prohibited by the B.C. Ministry of Environment.

The chemical 2-4-5-T was banned by the Canadian government in 1985.

Faced with similar stories of cancer stemming from exposure to 2-4-5-T, the province of Ontario has organized a fact-finding panel to find out just how much of the chemical was sprayed around the province in the 1950s and 1960s. Results from that panel are expected in June.

World Focus correspondent Mark Litke and producer Ara Ayer travel to Vietnam to report on the long term impacts of Agent Orange/Dioxin on the Vietnamese land and people. This video report was part of their series on New Vietnam.